1. Technical Field
The present invention relates to a stereo 3D navigation apparatus and a saliency-based camera parameter control method for the same.
2. Description of the Related Art
With recent advances in stereoscopic virtual reality equipment such as Oculus Rift, much attention is being focused on rendering methods related to stereoscopic visualization. However, mismatches between person's eyes and rendered images can cause visual fatigue accompanied by headaches, dizziness, nausea. As such, research is underway in various fields aiming to resolve this problem. An existing method for reducing visual fatigue may involve defining a visual comfort zone, in which a person may comfortably perceive a rendering, and controlling the parameters of the virtual cameras such that the scenes can be formed within the visual comfort zone, for instance by adjusting the distance between the virtual cameras and adjusting the depth of the virtual screen. However, besides camera parameters, other factors inherent in the scenes, such as color, textural patterns, etc., can also cause visual discomfort during a stereoscopic visualization process. This type of problem is associated with the visual perception characteristics of persons, and thus is difficult to resolve simply by changing the camera parameters. Existing techniques that take account such perceptual characteristics may include, for example, a method of extracting a saliency map from a 2-dimensional image and positioning places of high visual attentive objects in a zero parallax region based on the saliency map, and a method of using a head-mounted display to track the line of sight and positioning the places of most frequent viewing in a zero parallax region based on the tracking. With the present invention, information on an object of a high level of visual attention is detected by considering low-level saliency and high-level saliency in a 3-dimensional virtual space; where the low-level saliency is based on color and texture, and the high-level saliency relates to independent object information within the scene. This method, while utilizing aspects of existing methods for controlling the parameters of a virtual camera, makes it possible to change the parameters of the camera such that an object of high visual attention is located at a position of zero parallax, to thereby reduce factors causing visual discomfort, to levels unachievable with existing methods.